Bronchiolitis

Definition

Bronchiolitis is a common lung infection, often caused by a virus. It most frequently occurs in infants, commonly younger than 6 months of age. Typically, bronchiolitis occurs during the winter months.

Bronchiolitis starts out with symptoms similar to those of a common cold but then progresses to coughing and wheezing. Symptoms of bronchiolitis typically last for a week or two and then go away.

In some cases, especially if your child has an underlying health problem or is a significantly premature newborn, bronchiolitis can become severe and require hospitalization.

Bronchioles and alveoli

Bronchioles and alveoli

Within your lungs, the main airways (bronchi) branch off into smaller and smaller passageways, the smallest of which are called bronchioles. At the end of the bronchioles are tiny air sacs (alveoli). ...

Symptoms

For the first few days, the signs and symptoms of bronchiolitis are similar to those of a common cold:

• Runny nose
• Stuffy nose
• Slight fever (not always present)

After this, there may up to one week of:

• Wheezing — breathing seems more difficult or noisy when breathing out
• Rapid or difficult breathing
• Rapid heartbeat

In otherwise healthy infants, the infection generally goes away by itself in one to two weeks. If your child was born prematurely or has underlying health problems, such as a heart or lung condition or a weakened immune system, the infection may be more severe and your child may need to be hospitalized.

Severe bronchiolitis may cause marked difficulty breathing or bluish-looking skin (cyanosis) — a sign of inadequate oxygen. This requires emergency medical care.

When to see a doctor
If your child has more than minor breathing problems, is younger than 12 weeks old or has other risk factors for bronchiolitis — including premature birth or a heart or lung condition — contact your child's doctor.

If your child experiences any of the following signs and symptoms, seek prompt medical attention:

• Vomiting
• Breathing very fast — more than 40 breaths a minute — and shallowly
• Skin turning blue, especially around the lips and fingernails (cyanosis)
• Exhaustion from trying to breathe or the need to sit up in order to breathe
• Lethargy
• Refusal to drink enough fluids, or breathing too fast to eat or drink
• Audible wheezing sounds

Causes

Bronchiolitis occurs when a virus enters the respiratory system and makes its way to the bronchioles, which are the smallest of the airways branching off the two main breathing tubes (bronchi) within your lungs. The viral infection makes the bronchi swell and become inflamed. As a result, mucus often collects in these airways, which can make it difficult for air to flow freely through your lungs.

In older children and adults, the resulting signs and symptoms are generally mild. But an infant's bronchioles are much narrower than are an adult's and are more easily blocked, leading to greater difficulty breathing.

The respiratory syncytial virus (RSV), a common virus, causes most childhood bronchiolitis cases. The rest are caused by other infectious agents, including viruses that cause the flu or the common cold.

Bronchiolitis is a contagious condition. You contract the virus just as you would a cold or the flu — through droplets in the air when someone who is sick coughs, sneezes or talks. You can also contract bronchiolitis by touching shared objects — such as utensils, towels or toys — and then touching your eyes, nose or mouth.

Risk factors

One of the greatest risk factors for getting bronchiolitis is being younger than 6 months old, because the lungs and immune system aren't yet fully developed. Boys tend to get bronchiolitis more frequently than girls do.

Other factors that have been associated with an increased risk of bronchiolitis in children include:

• Never having been breast-fed — breast-fed babies receive immune benefits from the mother
• Premature birth
• An underlying heart or lung condition
• A depressed immune system
• Exposure to tobacco smoke
• Contact with multiple children, such as in a child care setting
• Living in a crowded environment
• Having siblings who attend school or child care and bring home the infection

Complications

Complications of severe bronchiolitis may include:

• Increasingly labored breathing
• Cyanosis, a condition in which the skin appears blue or ashen, especially around the lips, caused by lack of oxygen
• Dehydration
• Fatigue
• Severe respiratory failure

If these occur, your child may need hospitalization. Severe respiratory failure may require insertion of a tube into the trachea (intubation) to assist the child's breathing until the infection is brought under control.

If your infant was born prematurely, has a heart or lung condition, or has a compromised immune system, watch closely for beginning signs of bronchiolitis. The infection may rapidly become severe, and signs and symptoms of the underlying condition may become worse. In such cases, your child will usually need hospitalization to monitor his or her health and provide any necessary care.

Infrequently, bronchiolitis is accompanied by another lung infection such as bacterial pneumonia, which is treated separately. Reinfections with RSV after the initial episode may occur but typically aren't as severe. Repeated episodes of bronchiolitis may precede the development of asthma later in life, but the relationship between the two conditions is unclear.

Preparing for your appointment

You're likely to start by first seeing your family doctor or your child's doctor. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

• Write down any symptoms your child is experiencing, including any that may seem unrelated to an upper respiratory infection, and when they started.
• Write down key personal information, such as if your child was born prematurely or if he or she has a heart or lung problem.
• Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions ahead of time will help you make the most of your time together. List your questions from most important to least important in case time runs out. For bronchiolitis, some basic questions to ask your doctor include:

• What is likely causing my child's symptoms? Are there other possible causes?
• Does my child need any tests?
• How long do symptoms usually last?
• What is the best course of action?
• What are the alternatives to the primary approach that you're suggesting?
• Does my child need medication? If so, is there a generic alternative to the medicine you're prescribing me?
• What can I do to make my child feel better?
• Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend visiting?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

• When did your child first begin experiencing symptoms?
• Have your child's symptoms been continuous, or occasional?
• How severe are your child's symptoms?
• What, if anything, seems to improve your child's symptoms?
• What, if anything, appears to worsen your child's symptoms?

What you can do in the meantime
If your child has a fever, you can give him or her acetaminophen (Tylenol, others). Have your child drink plenty of fluids to prevent dehydration. Keeping your child upright and the air moist with a humidifier also may help ease congestion.

Tests and diagnosis

The doctor will likely listen to your child's lungs with a stethoscope to check for wheezing and prolonged breathing out (exhaling). These may indicate obstructed airflow in the bronchioles. The doctor may consider specific risk factors for bronchiolitis as well.

Sometimes other tests are recommended, including:

• Chest X-ray. In severe or uncertain cases, your doctor may request that a chest X-ray be taken to visually check for any signs of pneumonia. Your doctor may also check for the presence of a foreign object, such as a peanut or small piece of plastic, that your baby or toddler may have inhaled.
• Mucus sample test. In addition, your doctor may collect a sample of mucus from your child — using a nasal pharyngeal swab or a suction catheter that's gently inserted into the nose — to test for the virus that may be causing the bronchiolitis.
• Blood tests. Occasionally, blood tests might be used to check your child's white blood cell count. An increase in white blood cells is usually a sign that your body is fighting an infection. A blood test can also determine whether the level of oxygen has decreased in your child's bloodstream. An alternative test for oxygen levels is an oximeter that fits over the finger. Oxygen is necessary to the functioning of the body's organs, including the brain.

Your doctor may also ask you about signs of dehydration, especially if your child has been refusing to drink or eat or has been vomiting. Signs of dehydration include sunken eyes, dry mouth and skin, sluggishness, and little or no urinary output.

Treatments and drugs

You can treat most cases of bronchiolitis at home with self-care steps. Because viruses cause bronchiolitis, antibiotics — which are used to treat infections caused by bacteria — aren't effective against it. If your child has an associated bacterial infection, such as pneumonia, your doctor may prescribe antibiotics for that.

In more-severe cases, doctors may prescribe inhaled antiviral drugs, such as ribavirin (Rebetol). However, studies haven't found this drug to be consistently effective.

If your child has complications from bronchiolitis, a stay at the hospital may be necessary. At the hospital, your child will likely receive humidified oxygen to maintain sufficient oxygen in the blood, and perhaps fluids through a vein (intravenously) to prevent dehydration.

Lifestyle and home remedies

Although it may not be possible to shorten the duration of your child's illness, you may be able to relieve some of the symptoms and make your child more comfortable. Here are some tips to consider:

• Humidify the air. If the air in your child's room is dry, a cool-mist humidifier or vaporizer can moisten the air and help ease congestion and coughing. Be sure to keep the humidifier clean to prevent the growth of bacteria and molds. Keep the room warm but not overheated — too much heat can make the air drier. Another way to humidify the air is to run a hot shower or bath in the bathroom and let it steam up the room. Sitting in the room holding your child for about 15 minutes may help ease a fit of coughing.
• Keep your child upright. Being in an upright position usually makes breathing easier. Placing your infant in a car seat may help. If you plan to leave your child in a car seat for an extended period of time, such as for a nap, make sure your child's head won't fall forward, which can prevent proper breathing. To do this, place foam wedges or a rolled up blanket on each side of your child's head to keep it safely in place. Also check that the seat has an appropriate slope. This varies with the child's size and age.
• Have your child drink clear fluids. To prevent dehydration, give your child plenty of clear fluids to drink, such as water, juice or gelatin water. Your child may drink more slowly than usual, due to congestion.
• Try saline nasal drops to ease congestion. You can purchase these drops over-the-counter (OTC). They're effective, safe and nonirritating, even for children. Instill several drops into one nostril, then immediately use a child-sized nasal suction instrument with a small tube on one end and rubber bulb at the other to clear out the nostril (but don't push the bulb too far in). Repeat the process in the other nostril. If your child is old enough, you might teach your child how to blow his or her nose.
• Use OTC pain relievers. You can purchase these drops over-the-counter (OTC). They're effective, safe and nonirritating, even for children. Instill several drops into one nostril, then immediately use a child-sized nasal suction bulb to clear out the nostril (but don't push the bulb too far in). Repeat the process in the other nostril. If your child is old enough, you might teach your child how to blow his or her nose.
• Maintain a smoke-free environment. Smoke can aggravate symptoms of respiratory infections. If a family member smokes, ask him or her to smoke outside of the house and outside of the car.

Prevention

A baby may develop bronchiolitis after catching a virus from an adult or child who has a common cold. When you have a cold, wash your hands before you touch your baby, and consider wearing a face mask as well. Frequent hand washing in general reduces the spread of viruses that cause bronchiolitis. If your child has bronchiolitis, keep him or her at home until the illness is past to avoid spreading it to others.

These other simple but effective ways can help curb spread of the infection:

• Limit your child's contact with people who have a fever or cold. If your child is a newborn, especially a premature newborn, avoid exposure to people with colds in the first two months of life.
• Keep bathroom and kitchen countertops in your home clean. Be especially careful if another family member has a cold. To disinfect the area, you can use a solution of bleach and water made with a tablespoon of bleach per gallon of cool water. Don't mix in any other chemicals, as this can create a toxic chemical reaction. Always store homemade mixtures in a labeled container out of the reach of young children.
• Use a tissue only once. Discard used tissues promptly, then wash your hands or use alcohol hand sanitizer.
• Use your own drinking glass. Don't share glasses with others.
• Be prepared away from home. Keep a waterless hand sanitizer handy for yourself and for your child when you're away from home.
• Wash hands. Frequently wash your own hands and those of your child.

No vaccine available
There's no vaccine for bronchiolitis. But the medication palivizumab (Synagis) can help decrease the likelihood of RSV infections in infants with high risk of severe disease, as well as decrease the need for hospitalization and limit severity of the illness. Palivizumab is typically given through a single injection into a large muscle, such as the thigh, once a month during the peak RSV season — from November through March.

Palivizumab doesn't interfere with childhood vaccines. The expense generally limits its use to infants at particularly high risk of RSV infection, such as those born very prematurely or with a heart-lung condition or a depressed immune system.